Spinal anesthesia for a parturient with the triad of Currarino.

The triad of Currarino, also known as Currarino syndrome or complex, is a rare hereditary syndrome involving a bony sacral defect, an anorectal malformation and a presacral mass. Thus far, only 250 cases have been reported, but milder cases may not be recognized, and many cases may not be published. In addition to disorders of the gastrointestinal and urogenital tracts, sensory and motor deficits may be present. Currently, there are no reports of women with the triad of Currarino undergoing cesarean delivery with the use of neuraxial anesthesia. Neuraxial anesthesia in patients with congenital malformations of the spine may be complicated or contraindicated, depending on the level and severity of the anatomic abnormality. We present the case of a pregnant woman at 36 weeks of gestation who underwent uncomplicated neuraxial anesthesia for cesarean delivery. When neuraxial anesthesia is contemplated in such patients, they should first receive careful neurologic and radiologic evaluation.

Composition of alphavirus-like replication complexes: involvement of virus and host encoded proteins.

The RNA-dependent RNA polymerases (RdRp's) of plus-strand RNA viruses contain one or more viral proteins. These proteins contain polymerase (POL) motifs corresponding to the active sites of the polymerase proteins. Additionally, domains corresponding to RNA helicase (HEL), methyltransferase (MT) or proteinase activity of the RdRp may be present. Comparison of available sequence data showed that each class of domain can be subdivided into two or three subclasses, and resulted in the classification of plus-strand RNA viruses into three supergroups. Here, we review our current knowledge on the composition of the RdRp's of alpha-like viruses from supergroup III. The strategy for the expression of viral replicase proteins, their stoichiometry in the enzyme complex, their mutual interactions and their possible functions in RNA synthesis are discussed. Moreover, the review covers host proteins that have been identified in viral RdRp's and their possible role in RNA synthesis.

Alfalfa mosaic virus replicase proteins P1 and P2 interact and colocalize at the vacuolar membrane.

Replication of Alfalfa mosaic virus (AMV) RNAs depends on the virus-encoded proteins P1 and P2. P1 contains methyltransferase- and helicase-like domains, and P2 contains a polymerase-like domain. Coimmunoprecipitation experiments revealed an interaction between in vitro translated-P1 and P2 and showed that these proteins are present together in fractions with RNA-dependent RNA polymerase activity. A deletion analysis in the yeast two-hybrid system showed that in P1 the C-terminal sequence of 509 amino acids with the helicase domain was necessary for the interaction. In P2, the sequence of the N-terminal 241 aa was required for the interaction. In infected protoplasts, P1 and P2 colocalized at a membrane structure that was identified as the tonoplast (i.e., the membrane that surrounds the vacuoles) by using a tonoplast intrinsic protein as a marker in immunofluorescence studies. While P1 was exclusively localized on the tonoplast, P2 was found both at the tonoplast and at other locations in the cell. As Brome mosaic virus replication complexes have been found to be associated with the endoplasmic reticulum (M. A. Restrepo-Hartwig and P. Ahlquist, J. Virol. 70:8908-8916, 1996), viruses in the family Bromoviridae apparently select different cellular membranes for the assembly of their replication complexes.

Apoptosis in developing anthers and the role of ABA in this process during androgenesis in Hordeum vulgare L.

Intra-nucleosomal cleavage of DNA into fragments of about 200 bp was demonstrated to occur in developing anthers, in which microspores had developed into the mid-late to late uni-nucleate stage in situ, i.e. at the verge of mitosis. The same was observed, but to a much larger extent, if these anthers were pre-treated by a hyper-osmotic shock. Pretreatment of anthers before the actual culture of microspores was required for optimal androgenesis of microspores. The use of the TUNEL reaction, which specifically labels 3' ends of DNA breaks, after intra-nucleosomal cleavage of DNA, revealed that DNA fragmentation mainly occurred in the loculus wall cells, tapetum cells and filament cells. TUNEL staining was absent or infrequently observed in the microspores of developing anthers in situ. Electron microscopy studies showed condensed chromatin in nuclei of loculus wall cells in the developing anthers. These observations at the chromatin and DNA level are known characteristics of programmed cell death, also known as apoptosis. Features of apoptosis were infrequently found in microspores from freshly isolated mature anthers. However, most tapetum cells had disappeared in these anthers and the remaining cell structures showed loss of cellular content. The viability of microspores in pre-treated anthers was comparable to those in freshly isolated anthers and almost four times higher than in anthers from control experiments. This observation was correlated with three to four times less microspores showing TUNEL staining and a two times higher level of ABA in the anther plus medium samples than in controls. Addition of ABA to the controls enhanced the viability and lowered the occurrence of apoptosis linked characteristics in the microspores. These data suggest that pre-treatment is effective in stimulating androgenesis because it leads to an increase in ABA levels which protects microspores from dying by apoptosis.